Fish locomotion and biomechanics as limiting and optimizing factors in fish passage

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Swimming ability determines how well fish are able to access habitat, and is a fundamental design consideration for passing fish at dams, road crossings, etc. The purpose of this study plan is to improve understanding of how fish are able to negotiate zones of high velocity and turbulent flow, such as are found in fishways, culverts, as well as in natural areas. Swimming performance is limited by the ability of fish to propel themselves through the water, which is governed by body shape, muscle and fin structure, etc. Behavior is also important, and species vary in how well they are able to apply their abilities to traverse barriers. These characteristics are important for providing access to habitat, and understanding them is also an important tool for preventing invasive species from colonizing new habitats. This information can be used to interrupt key life-history processes of invasive species, leading to control and potentially eradication in some instances.

Several projects are being performed under this study plan, with the overarching goal of acquiring data on swimming abilities and understanding how hydraulics interact with physiology and behavior to either limit access to habitat, or alternatively to inform engineering designs of fish passage structures. The ABiKiS provides direct measurements of how flow conditions affect distance that can be traversed as well as more fundamental metrics such as the relationship between swim speed and time to fatigue. An additional metric that has emerged through the course of this study is attempt rate—this is an index of motivation and is strongly influenced by hydraulic conditions and varies widely among species and with environmental conditions such as water temperature.

Photo of the ABiKiS viewed from the upstream end. The pipe to the left supplies flow. The gate valve in the foreground regulates velocity.

Turbulence has important effects on locomotion. The ABiKiS allows for study of controlled turbulence. White pipes and wires are PIT antennas, which are used to monitor movements of fish as they attempt to swim through this flow.

Sea lamprey are invasive in the Great Lakes. By attaching to smooth surfaces they are able to ascend traverse high velocity flows. We are studying swimming ability as well as methods for preventing attachment.